Re: Re: using main package variables within a module

I don't like it either ;)

I'm really wanting to understand why my $one isn't working, I think it's in scope!

As I explained above, I'll also be wanting to access variables from my config file - something like below, expect this doesn't work.

test.pl

#!/usr/bin/perl -wT
use strict;
use lib '/home/4220/straitwa/www.straitway.net/shop_34/lib';
use Shop;

my ($conf);

#open the config file and parse it
unless ($conf = do ('/home/4220/straitwa/www.straitway.net/shop_34/con
+f.pl')) {
  die ("Could not open config file");
}

Shop::db_connect;
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Shop.pm

package Shop;

use strict;
use Exporter;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);

$VERSION = 1.00;
@ISA = qw(Exporter);
@EXPORT = ();
@EXPORT_OK = qw(db_connect);

sub db_connect {
    print $conf->{'db_database'};
}

1;
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conf.pl

{
    db_database => 'straitway_1',
}
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What I'm wanting is the module Shop.pm to use the data in conf.pl, but I'm getting the error message

Global symbol "$conf" requires explicit package name at /home/4220/str
+aitwa/www.straitway.net/shop_34/lib/Shop.pm line 13.
Compilation failed in require at ./test.pl line 4.
BEGIN failed--compilation aborted at ./test.pl line 4.
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Re: Re: Re: using main package variables within a module by mfriedman (Monk) on Jun 17, 2002 at 18:11 UTC
I'm really wanting to understand why my $one isn't working, I think it's in scope! But it's not in scope. :) The problem you're having is because you're trying to access a lexical (my) variable outside of its lexical scope. That's a no-no. Only package variables can be accessed via their full package name. As an example of why this is, consider the following: `if ($foo == 3) { my $bar = 1; } else { my $bar = 1; }` [download] Here you've got two distinct $bar's, each one in a different lexical block. If you said $main::bar, and Perl allowed outside access to lexicals, how would Perl know which $bar to give you? It can't. That's why $main::bar can only refer to a package global. Since you're using strict, you have to declare it with a fully qualified name. That means you'll need to call it $main::bar (or $::bar, for short) when you declare it in test.pl.	[reply] [d/l]

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Re: Re: Re: using main package variables within a module
by mfriedman (Monk) on Jun 17, 2002 at 18:11 UTC

I'm really wanting to understand why my $one isn't working, I think it's in scope!

But it's not in scope. :)

The problem you're having is because you're trying to access a lexical (my) variable outside of its lexical scope. That's a no-no. Only package variables can be accessed via their full package name.

As an example of why this is, consider the following:

if ($foo == 3) { 
    my $bar = 1;
} else { 
    my $bar = 1;
}
[download]

Here you've got two distinct $bar's, each one in a different lexical block. If you said $main::bar, and Perl allowed outside access to lexicals, how would Perl know which $bar to give you? It can't. That's why $main::bar can only refer to a package global. Since you're using strict, you have to declare it with a fully qualified name. That means you'll need to call it $main::bar (or $::bar, for short) when you declare it in test.pl.

[reply]
[d/l]